Weak northern Stau (with retour d'est?)

The conditions in the Alps are pretty awesome at the moment. There’s a lot of snow pretty much everywhere. But you have to take care anyway. Snow drift and Gleitschnee avalanches are possible and the snowcover is pretty thin in Graubünden, the Waadtlander Alps, the French southern Alps and Süd-Tirol, so sharks are waiting below the surface. For the current snow reports and the three most important risks at the moment, check out this article.

I had some doubts about this forecast. I said in the office last Monday that it’s striking that western jetstream is lacking for weeks and the long term projections aren’t too positive about that either. Snow has to come from north/south circulations and that’s pretty hard with a powerful high pressure area above the Atlantic. Which is the situation right now.The high pressure area Traude

With situations like that the outcome is in the details. When the high pressure area will move west, the gates will open for cold and humid air from the north. But when good old Traude will move to the east a little bit, all the fronts can’t pass (and when they succeed in passing the high pressure area they lost a lot of powder). But the sting might be in the Gulf of Genua. When the cold air succeeds in getting to the Mediterrenean in this north/south circulation, it will result in a Genua low (also known as a Retour d’est).

But hey, it’s only Tuesday and I can’t give you any details till Thursday. What I can tell you right now is that a weak northern Stau is approaching. It will arrive in the northern Alps on Friday/Saturday. You can expect around 5-15 centimeters of freshies deep into the valleys. Especially the first mountains in the Alps will take advantage of that. Because this cold air will reach the Meditereanean, it might result in a small retour d’est that will bring snow (around 5-25 centimeters) to the Piemonte. But please, don’t start your engines yet, because a high pressure area is waiting for the long term. More details tomorrow, an advice for the weekend on Thursday!